Cpgp day01-session 5 - drawing a process flow diagram 2012 final

Drawing a Process Flow Diagram

What is a PFD

• A process flow diagram is a pictorial representation of what is happening in a process in a sequential order

• It is a snapshot of the process at the time of inspection

• It is a paper based tool

Why Draw a PFD

• Industries do not know

– What is wasted– Where is it generated

– How much is wasted

PFD for Cleaner Production

A simple diagram which uses only three main symbols and one auxiliary symbol

Not to be confused with other types of diagrams

Symbols to be Used

Rectangle is used for representing a process step

Arrow is used to show link and direction

Ellipse represents the beginning and the end of diagram

A Circle (with character or sign) is used to show continuation of a process

Tips in drawing a PFD

• List all the process steps prior to drawing PFD• Break larger steps into simpler steps as much as

possible• The PFD is drawn from top to bottom of a paper• Arrows link process steps in sequential order• Arrows linking process steps must always be

directed downwards (Top to Bottom PFD)• Labour, Time and Capital equipment not

included as inputs or waste streams• Inputs should be consumable items/material only

Always Start With an Ellipse

• Draw an ellipse on the top of the page and • Insert the name of the main raw material

which undergoes the change to form the final product within it

Raw Peanuts

Drawing Process Steps

• Process steps (activities) are depicted by rectangles

• Rectangles are drawn below the elipse, one per process step

• Sequential process steps (are linked by downward arrows

• Insert the name of the process step inside the rectangle

Storing

Raw Peanuts

De-shelling

Sorting

Frying

Indicating Resources Used

• Resources used are known as INPUTS

• Inputs are indicated on the left side of the rectangles (process steps)

• Inward arrows are drawn from each input material towards the rectangle

• Inputs are consumable material used to carry out the change to the main raw material at each process step

Electricity(Lighting)

LP GasCoconut Oil

Hot air

Storing

Raw Peanuts

De-shelling

Sorting

FryingElectricity(Lighting)


Indicating Waste Streams

• Waste streams are known as OUTPUTS• Outputs are indicated on the right side of

the rectangle • Outward arrows are drawn towards each

Output stream from the rectangle• All waste stream generated at this point

should be indicated on the PFD

Shells Spilt nuts Dust

Oil SpillsNut spillsOil EvaporationWaste HeatExcess gasOver fried nuts

Storing

Raw Peanuts

De-shelling

Sorting

FryingLP Gas

Coconut Oil

Hot air




Energy Loss

Foreign Matter Spilt nuts Dust

How to End the PFD

• The PFD is ended with an elipse depicting the finished product

Main Raw material

Finished product

Inputs Outputs

Shells Spilt nuts Dust

Oil SpillsNut spillsOil EvaporationWaste HeatExcess gasOver fried nuts

Storing

Raw Peanuts

De-shelling

Sorting

FryingLP GasCoconut Oil

Hot air




Energy Loss

Foreign Matter Spilt nuts Dust

Oil DrainingOil Paper Drained Oil Used Oil Paper

Salting

Packing

Salt Spilt Salt Spilt nuts

Packing Material Rejected Packing MaterialSpilt NutsOverfilled packs

Fried Salted Peanuts

Continuation

• If one page is insufficient to complete the PFD, use another.

• Do not try to draw two PFDs on one paper.

• Arrows are never directed upwards

The following method is not correct

The following method though correct is not preferred

The following method is correct and preferred

Major Raw Material

A

Page 1

Finished Product

APage 2

Repeated Processes

Filtering

Mixing

Bagasse

Juice 1

Water

Electrical Energy

Sugar Cane

Crushing

Juice 2 Juice 3

Electrical Energy

FilteringBagasseElectrical

Energy

Mixing

Filtering BagasseElectrical Energy

Water

Electrical Energy

Branching

Preparing

Dyeing Printing Bleaching

Combining

Dyeing Printing Bleaching

Finishing

Auxiliary Processes

• Auxiliary processes are those that support the main process.

• They include cleaning, Bottle washing, Steam Generation, Water treatment etc.

• PFD for Auxiliary processes should be drawn separately and linked to the main PFD

Chemical SpillsWaste Chemicals

Cleaning

Chemical Washing

Hot water rinsing

First Washing

Bottles

Cleaned Bottles

B

Water

Electricity (Lighting)




Chemicals

Hot Water

Energy Loss

Energy LossWater SpillsWaste Water

Energy Loss

Energy LossHot Water SpillsWaste Water

Boiling(Boiler)

FuelChemicals

Air

Flue Gas lossRadiation Heat lossSteam LeaksBlow-down loss

Water

Steam

A

Page 2

Mangoes

Washing

Peeling & Cutting

Crushing

Mixing

Page 1

Finished Product

Cooking

Cooling

Bottling

Labelling and Storing

Electricity (Lighting) WaterElectricity (Lighting)

Electricity

Electricity

SteamElectricitySugar

Electricity

BottlesElectricityCaps

ElectricityLabels

A

B

How to Indicate Cleaning Processes

• Pay attention to processes such as cleaning operations– Floor Cleaning– Machine Cleaning– Equipment Cleaning

• Such operations should also be indicated on the PFD

This Method is Wrong!

Mangoes

Washing

Peeling & Cutting

Crushing

Mixing

Bottled Mango Juice

Cooking

Cooling

Bottling



Electricity

Electricity


Electricity


ElectricityLabels

A

B

WaterDetergents

How to Indicate Cleaning of the Juice Cooking Pan Page 1

Mangoes

Washing

Peeling & Cutting

Crushing

Mixing

Bottled Mango Juice

Cooking

Cooling

Bottling



Electricity

Electricity


Electricity


ElectricityLabels

A

B

C

Page 2

Washing


C Pan Cleaning Process

Detergents

Hot Water

Energy Loss

Waste Water

Water Spills

Detergent Spills

PFDs for Services

• The PFD for a service organization may be drawn as a block diagram/Unit Process

• These are prepared for activities that do not have sequential steps, such as Boilers, Housekeeping activities in Hotels, Kitchen activities in Hotels etc.

House keeping

Room

Cleaned Room

Energy

Room cleaning chemicals

Cotton Rags

Toilet cleaning chemicals

Tissue Paper

Toilet paper rolls

Use of Use of Raw MaterialsRaw Materials ManufactureManufacture DistributionDistribution UseUse DisposalDisposal

Product Life CycleProduct Life Cycle

For PFDs are not drawn for products We can draw Life Cycle Diagrams

Can we Draw PFDs for Products?

Wording

• All process steps are considered to be dynamic (process step is taking place at the time of observation)

• Therefore all steps are referred in present continuous – Checking

FryingDyeingDrying

• Do not Mention the equipment as the process step

• These terms are wrong- Dry - Dye - Fry- Dried - Dyed - Fried- Dryer - Dying Machine - Frying Pan

Additional points

• However small the resource quantity may be indicate it on the PFD.

• However small the waste stream may be indicate it on the PFD.

• When considering the process steps the normal, abnormal, occasional ,accidental and maintenance operations should also be taken into account

Other Tools

Ecomapping - One little picture says more than a long speech !

• A visual, simple and practical tool to analyse and manage the environmental performance of companies industries

• An easy, creative and systematic method of obtaining environmental data

• An awareness - creation and learning tool based on the physical reality of the company

• A dynamic inventory of the changes in the environmental behaviour of the company

How to Use Eco-maps• Indispensable materials

– A4 -sized paper and a photocopy machine.• Time needed

– Less than one hour of work for each map.• When to do it?

– After the end of the accounting year.• How often should they be up-dated ?

– Once a year, or if the site is renovated, or activities are extended.

• Filing– With documentation for your environmental

management system, with your annual accounts .• Who can use them?

– The maps can be used by many different types of companies: from small manufacturing and service companies to large structures and local authorities.

How to Eco-map

1. Prepare Map of the urban situation

• Make a map of the site, seen from above, including car parks, access areas, roads and the surrounding environment.

• It should show the real situation.

2. Map of the site• Draw the outline of the site using

a scale and showing the interior spaces. This map should be copied and will be the basis for the work to be done.

• The maps should show the real situation - they should be simple, recognisable and in proportion. Maps should have a date, a name and a reference. Integrate one or two significant objects such as machines and boilers, which will enable the user to orient himself with the site easily

• If the site covers very different areas, individual maps of the different areas can be prepared and brought together.

3. Symbols• Develop your own

symbols, but use at least two Hatched lines: small problem (area to be monitored, problem to be studied)

• Circle: large problem (stop, corrective action)

• The more serious the problem, the thicker the circle

Case Study

Cpgp day01-session 5 - drawing a process flow diagram 2012 final

Environment

Transcript of Cpgp day01-session 5 - drawing a process flow diagram 2012 final